factor of treatment group. Statistical significance was defined
as P=0.05 determined using 2-tailed tests of the null hypothesis.
Values were adjusted for multiple imputations. Missing efficacy
data of lesion counts and EGSS data were estimated using the
Markov Chain Monte Carlo method. All statistical analyses were
performed in SAS® version 9.3 or later. Cutaneous safety and
tolerability assessments were summarized using descriptive
statistics. AEs were recorded and classified using the Medical
Dictionary for Regulatory Activities (MedDRA) terminology. Imputations
were not made for missing safety data.
RESULTS
Participants
The overall pooled study population in the phase 3 studies included 1614 participants who received tazarotene 0.045% lotion (n=799) or vehicle lotion (n=815).17 In this post hoc analysis, the population was segmented by race (n=1191 white, n=262 black) and by ethnicity (n=352 Hispanic, n=1262 non-Hispanic; Table 1). The black subpopulation was, on average, slightly older and had a higher proportion of female participants compared with the white subpopulation. Disease characteristics were similar between the races, although a slightly higher proportion of white participants had an EGSS of 4 compared with black participants (10.0% versus 4.6%, respectively). The subpopulations defined by ethnicity were similar in age and sex. While the majority of both the Hispanic and non-Hispanic subgroups were white, the non-Hispanic subgroup had higher proportions of participants reporting black or Asian race (Table 1).
Efficacy
Inflammatory and noninflammatory lesion counts decreased over time across all racial and ethnic subpopulations. In white participants, LS mean percent change from baseline in inflammatory lesions was significantly greater in the tazarotene 0.045% lotion group compared with the vehicle group at week 12 (-57.6% vs -45.0%; P<0.001); significant improvements were also observed at week 8 (Figure 1). Tazarotene-treated black participants had a similar reduction in inflammatory lesions (-60.4%) to white participants at week 12, but with no significant differences relative to vehicle. For noninflammatory lesions, reductions from baseline were significantly greater with tazarotene 0.045% lotion than vehicle at week 12 for both race groups (P<0.001, white; P<0.05, black); significant improvements were observed as early as week 4 in white participants and week 8 in black participants (Figure 2).
In the subpopulations defined by ethnicity, LS mean percent change in inflammatory lesion counts were significantly greater with tazarotene 0.045% lotion versus vehicle at week 12 in the Hispanic and non-Hispanic groups (P<0.01, Hispanic; P<0.001, non-Hispanic; Figure 3). Similar trends were observed in noninflammatory lesion counts, with significant improvements following treatment with tazarotene 0.045% lotion versus vehicle at week 12 (P<0.01, Hispanic; P<0.001, non-Hispanic; Figure 4). In non-Hispanic participants, significant decreases were observed as early as week 4 for noninflammatory lesions and week 8 for inflammatory lesions.
Rates of treatment success were higher following treatment
The overall pooled study population in the phase 3 studies included 1614 participants who received tazarotene 0.045% lotion (n=799) or vehicle lotion (n=815).17 In this post hoc analysis, the population was segmented by race (n=1191 white, n=262 black) and by ethnicity (n=352 Hispanic, n=1262 non-Hispanic; Table 1). The black subpopulation was, on average, slightly older and had a higher proportion of female participants compared with the white subpopulation. Disease characteristics were similar between the races, although a slightly higher proportion of white participants had an EGSS of 4 compared with black participants (10.0% versus 4.6%, respectively). The subpopulations defined by ethnicity were similar in age and sex. While the majority of both the Hispanic and non-Hispanic subgroups were white, the non-Hispanic subgroup had higher proportions of participants reporting black or Asian race (Table 1).
Efficacy
Inflammatory and noninflammatory lesion counts decreased over time across all racial and ethnic subpopulations. In white participants, LS mean percent change from baseline in inflammatory lesions was significantly greater in the tazarotene 0.045% lotion group compared with the vehicle group at week 12 (-57.6% vs -45.0%; P<0.001); significant improvements were also observed at week 8 (Figure 1). Tazarotene-treated black participants had a similar reduction in inflammatory lesions (-60.4%) to white participants at week 12, but with no significant differences relative to vehicle. For noninflammatory lesions, reductions from baseline were significantly greater with tazarotene 0.045% lotion than vehicle at week 12 for both race groups (P<0.001, white; P<0.05, black); significant improvements were observed as early as week 4 in white participants and week 8 in black participants (Figure 2).
In the subpopulations defined by ethnicity, LS mean percent change in inflammatory lesion counts were significantly greater with tazarotene 0.045% lotion versus vehicle at week 12 in the Hispanic and non-Hispanic groups (P<0.01, Hispanic; P<0.001, non-Hispanic; Figure 3). Similar trends were observed in noninflammatory lesion counts, with significant improvements following treatment with tazarotene 0.045% lotion versus vehicle at week 12 (P<0.01, Hispanic; P<0.001, non-Hispanic; Figure 4). In non-Hispanic participants, significant decreases were observed as early as week 4 for noninflammatory lesions and week 8 for inflammatory lesions.
Rates of treatment success were higher following treatment
